Text Structure and Purpose on the SAT Reading and Writing test asks students to identify why a passage is organized as it is and what a sentence or the whole text is doing. Students must separate overall aim from the local job of a detail in science write-ups, field experiments, and short novel scenes. Questions typically highlight a sentence or the full text and ask what it mainly accomplishes. Answer choices are brief purpose statements led by verbs such as to illustrate, to qualify, or to note a limitation. Common traps restate content instead of function or treat a side detail as the main goal.
Question 1
Marine biologist Imani Cho found that rockfish sheltered beneath kelp more often in harbors than along the open coast. The harbor surveys recorded where kelp was present but did not measure wave action, which also tends to be milder in harbors. Thus, researchers could not tell whether the fish preferred the kelp itself or the calmer water that often occurred around it. Cho’s team tested fish in tanks where kelp and water movement varied independently.
Which choice best describes the function of the underlined sentence in the text as a whole?
- AIt states the conclusion that Cho’s team reached after conducting its tank experiments.
- BIt explains why previous surveys found more juvenile rockfish along the open coast.
- CIt identifies the uncertainty that Cho’s team designed its experiments to resolve.
- DIt suggests that Cho’s team expected kelp to affect water movement in its tanks.
Show answer
Answer: C — It identifies the uncertainty that Cho’s team designed its experiments to resolve.
The underlined sentence presents two possible reasons for the same observation. The final sentence shows that Cho’s team varied those factors independently to determine which reason was responsible.
Question 2
A city tested a reflective roof coating meant to keep buildings cool. On warehouses with unshaded metal roofs, the coating reduced midday indoor temperatures by several degrees. On apartment buildings shaded by taller neighbors, however, it produced almost no change. Researchers concluded that the coating’s benefit depends partly on how much direct sunlight a roof receives.
Which choice best describes the function of the underlined sentences in the text as a whole?
- AThey demonstrate that the coating’s effectiveness varies with the conditions in which it is used.
- BThey show that apartment buildings are generally warmer indoors than warehouses are.
- CThey explain why the city selected metal roofs rather than other kinds of roofs for the test.
- DThey establish that shade from nearby buildings is more costly than applying a reflective coating.
Show answer
Answer: A — They demonstrate that the coating’s effectiveness varies with the conditions in which it is used.
The coating helps substantially in the unshaded case but barely helps in the shaded case. This contrast supports the conclusion that exposure to direct sunlight affects the coating’s usefulness.
Question 3
The following text is adapted from Dalia Herrera’s 2017 novel The Brass Gear. Mara watches her aunt repair a clock.
Mara feared that it would never chime again. Her aunt chose a brass gear, polished it, and fitted it into place. The hands began to move. The little click from inside the clock sounded to Mara like a confident answer. Mara released the breath she had been holding.
Which choice best describes the function of the underlined sentence in the text as a whole?
- AIt suggests that Mara is disappointed by how quietly the repaired clock operates.
- BIt emphasizes that the clock’s return to working order reassures Mara.
- CIt indicates that Mara understands exactly how her aunt repaired the clock.
- DIt reveals that Mara had doubted whether the clock needed a new gear.
Show answer
Answer: B — It emphasizes that the clock’s return to working order reassures Mara.
Mara hears the clock’s click as a “confident answer,” and she relaxes immediately afterward. The sentence therefore conveys her relief that the repair has succeeded.
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